1. Technical Field
The present invention relates to a projector-type vehicle headlamp.
2. Related Art
In the related art, a vehicle headlamp is generally configured such that a projection lens is disposed on an optical axis extending in a longitudinal direction of a vehicle. Also, a light source is disposed to the rear of a rear focal point of the projection lens. As a result, light from the light source is reflected close to the optical axis by means of a reflector.
In relation to such a projector-type vehicle headlamp, Japanese publications JP-A-2-47704 and JP-A-2001-229715 disclose a lamp configuration of a lateral-insertion type, wherein a light source includes a light-emitting section of a light source bulb that is fixedly inserted into a reflector in a lateral direction in relation to the optical axis.
When such a lamp configuration is of the related art lateral-insertion type, the lamp can be reduced in longitudinal length to be miniaturized.
However, in the vehicle headlamp disclosed in the above-described publications, the light source bulb is fixedly inserted into the reflector within a horizontal plane that includes the optical axis. Accordingly, at least the following related art problem arises.
In a related art projector-type vehicle lamp, a region lateral to the optical axis on a reflection surface of a reflector is suitable for forming a diffusion region of a light distribution pattern. However, when the light source bulb is fixedly inserted into the reflector within a horizontal plane that includes the optical axis, a hole for insertion and fixation of the light source bulb is formed on the region lateral to the optical axis on the reflection surface.
Accordingly, there is a related art problem in that the region lateral to the optical axis cannot be effectively used for light distribution control. Further, ensuring sufficient brightness of the diffusion region of the light distribution pattern becomes difficult.